1. Field of the Invention
The present invention generally relates to a proposal for improving a left-right wheel drive force distribution control apparatus that is useful for a vehicle, particularly a four-wheel drive vehicle.
2. Background Information
Japanese Laid-Open Patent Application Publication No. 08-121571 (FIG. 2) presents an example of a conventional left-right wheel drive force distribution control device for a vehicle. Regarding controlling a distribution of drive forces to left and right non-main drive wheels, when the vehicle is operating in a small lateral acceleration region, the proposed technology executes control such that a larger drive force difference (only a smaller drive force difference) is imposed between the left and right non-main drive wheels when a lateral acceleration is larger (smaller). Meanwhile, when the vehicle is operating in a large lateral acceleration region, the proposed technology executes control such that a only a smaller drive force difference (a larger drive force difference) is imposed between the left and right non-main drive wheels when the lateral acceleration is larger (smaller).
With such a left-right wheel drive force distribution control, when the vehicle is in the small lateral acceleration region, a braking/drive force of a turning-direction inside wheel increases as the lateral acceleration increases and the turning performance and high-speed stability can be improved. Meanwhile, when the vehicle is in the large lateral acceleration region, the braking/drive force of the turning-direction inside wheel decreases as the lateral acceleration increases and a cornering force can be secured as planned.